Articles in Spanish generally agree in number and gender with nouns and adjectives.
1. el chico (the boy) los chicos (the boys)
2. la pluma (the pen) las chicas (the pens)
3. el chico alto (the tall boy) los chicos altos (the tall boys)
4. la casa blanca (the white house) las casas blancas (the
white houses)
Definite articles are:
el
los
la
las.
Indefinite articles are:
un
una
unos
unas
5. un libro (a book) unos libros (some books)
6. una mesa (a table) unas mesas (some tables)
7. un plato grande (a large plate) unos platos grandes (some large plates)
8. una silla roja (a red chair) unas sillas (some red chairs)